1243026861 has 16 divisors (see below), whose sum is σ = 1689849216. Its totient is φ = 812467136.

The previous prime is 1243026853. The next prime is 1243026901. The reversal of 1243026861 is 1686203421.

It is a cyclic number.

It is not a de Polignac number, because 1243026861 - 2³ = 1243026853 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1243026361) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 426736 + ... + 429638.

It is an arithmetic number, because the mean of its divisors is an integer number (105615576).

Almost surely, 2^1243026861 is an apocalyptic number.

It is an amenable number.

1243026861 is a deficient number, since it is larger than the sum of its proper divisors (446822355).

1243026861 is a wasteful number, since it uses less digits than its factorization.

1243026861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5652.

The product of its (nonzero) digits is 13824, while the sum is 33.

The square root of 1243026861 is about 35256.5860655850. The cubic root of 1243026861 is about 1075.2105190018.

The spelling of 1243026861 in words is "one billion, two hundred forty-three million, twenty-six thousand, eight hundred sixty-one".